Poll: What's your KT150 bias set to per tube (ma?)

In my case I could go even higher on bias +5-10ma more, and remain in spec. First time I experimented with wider adjustment sweeps since amps were new. Seems I originally underestimated KT150s ability to sound more lush and "tubey". It is possible, and discovered it a bit later with my amps after months of burn-in of all tubes, upgraded coupling caps, and more. Felt kinda stupid once I found the proper bias setting window many months months later, like "ah, there it is!", thus realizing KT150s can do it too if I simply adjusted bias to the sweet spot, duh...

Now I have no desire to go back to KT88s, KT77s, or EL34s (or back to my former parallel strapped triode based amps) any more. Was not expecting this realization to actually happen with my particular KT150 mono amps, and it just did. Ultra conservative low-biasing is no longer an option, the higher bias is well worth it now :)

I learned that the hotter I bias the BETTER the lower listening levels are.

If I bias to hot then the upper listening levels suffer. It has to do with performance vs SQ. So if there is a party coming up and your going to be turning it up a bit, its best to bias down a bit. If your doing a lot of late night low level listening, bias hotter.. They just sound better, cleaner and sharper. IF your using them for bass, TOO, it’s kind of a happy medium to bias in the middle so to speak..

If you could limit the bass duty on the valves, I think you’d really be surprised. Valves really don’t transition as well as SS from say 40hz and then 5Khz then back to 100 hz.. Remove that duty, 300 hz and down.. Valve amps REALLY preform much better.

That is where EL34, 6550 and even KT88 do a whole lot better too, NOT doing bass. If you can cut from 80-100hz and down, its night and day especially EL34.. They just come alive, when you LOSE the bass duty.

I like 6L6 if a valve amp is going to do full range. I think it’s the best of ALL the valves even KT66s (VERY close) They can take the punishment too especially the mil spec 6L6. 6V6 is really good too, if you get enough going at one time.. Lovely valves..

I would like to have about 4-6 sets of quad RCAs 55-65 vintage.
Coke bottles 4, sets of quads would be fine.. Macs (MC30,40,240s) and Cary both just loved RCAs BPs.

Regards

@oldhvymec - If you could limit the bass duty on the valves, I think you’d really be surprised.

An unexpected added surprise was the lower register midrange and upper bass range that just came through biasing up on the KT150s. I usually run custom 12" Scanspeak active subs for 50hz below in my setup. Now after having biased up the main mono tube amps, immediately had to turn the sub down, off, almost don’t need it. oldhvymec, i know you know the "sound", its reminiscent tone and sound closer to running two V12R mono blocks, yet I’m running only (4) KT150s instead of (12 or 24) EL34s across two mono V12Rs. Using Mullard Blackburn mid 60s dual-triode 12AU7, 12AT7/CV4024s in front of the KT150s to shape tone. Also worth noting, Mundorf Silver-Gold EVO coupling caps (same as my former Cary amps had) now in my current KT150 mono amps. This too brought the KT150s to another level with nice tone and texture, probably closer to what you might know from a V12R with these same caps paired in Cary amps and GL KT88s, a tad more transparent than EL34s.

Interesting, I haven’t ran 120 or 150 so I just don’t know. BUT it is good to know.. I’ve used the valves I use so long and the supplies I have are all about 6V6, 6L6, El34, 6550, KT88, KT90. I doubt I would change.. BUT I should never say never.. Things change, that’s the only thing for sure..

Just like a lot of folks like running single ended. I NEVER have, I’ve had a few SET, 300B la te da.. Every time I go back to A/B or UL.. Just my speakers and my ears.. Small planars and fast tubes work for me.. Bloated or slurry along valve units just turn me OFF. Not much of a Flea Watt guy..

Sounds like you have a GREAT setup.. I gotta get out more..

I have been looking at a pair of late model Cary SE though.. We’ll see
I sure do like my V12R NOW. It had changed a LOT from when I got it.
The biggest change for me was the signal caps.. I went to silver Jensens, THAT change it from a tubie sound to laser imaging, pinpoint clarity.. I’m sure it would preform well doing bass with a few of the speakers I own.. That is a serious amp. NOW, Before. Nice!, Never a serious contender against my MC240s.. Sure is now....

Still HEAT.. is a killer for me.. I can't take the heat from them in the summer months.. BUT I did lower the heat index a bit.. 6V6s and new filter caps with a little tweak.. I can make it to the end of June.. and start back up mid Oct.

Regards

All that blabbing and still didn't say..

BIAS differently makes a difference.. :-) Things are not set in stone from valve to valve either. Some brands of valves act different too..